Effects of High Temperature on Rice Grain Development and Quality Formation Based on Proteomics Comparative Analysis Under Field Warming

Abstract

With the intensification of global warming, rice production is facing new challenges. Field evidence indicates that elevated temperature during rice grain-filling leads to the further deterioration of grain quality. In order to clarify the potential regulatory mechanism of elevated temperature on the formation of rice quality, the DIA mass spectrometry method under the background of field warming was conducted to investigate the regulatory effects of high temperature on grain development and material accumulation pathways. The results showed that a total of 840 differentially expressed proteins were identified during the grain-filling process under elevated temperature. These differentially expressed proteins participated in carbon metabolism, amino acid biosynthesis, signal transduction, protein synthesis, and alternately affected the material accumulation of rice grains. The significant up-regulation of PPROL 14E, PSB28, granule-bound starch synthase I, and the significant down-regulation of 26.7 kDa heat shock protein would lead to the component difference in grain starch and storage proteins, and that could be responsible for the degradation of rice quality under elevated temperature. Results suggested that proteins specifically expressed under elevated temperature could be the key candidates for elucidating the potential regulatory mechanism of warming on rice development and quality formation. In-depth study on the metabolism of storage compounds would be contributed in further proposing high-quality cultivation control measures suitable for climate warming.

High temperature boosts resistant starch content by altering starch structure and lipid content in rice ssIIIa mutants

“…During grain development, an increment in temperature of 1.6°C-3.1°C can disturb the accumulation of storage materials (Liu et al, 2021). Previous studies showed that HT can increase protein content (Lin et al, 2010) and was unfavorable for lipid accumulation during rice grain ripening.…”

“…Variations in AAC under HT may also be dependent on rice varieties. Cheng et al (2005) found that HT increased the AC in high-AC varieties, while Liu et al (2021) found that AC decreased under elevated temperatures. The different responses of AAC in R7954 and mutants RS111 and RS4 to HT (Table 1) might be because of the increased sensitivity of amyloplast enzymes in RS111 and RS4 exposed to HT.…”

“…Generally, HT leads to a declined expression of many starch biosynthesis genes such as GBSSI, BEs, cyPPDK (Jiang et al, 2003;Yamakawa et al, 2007; and SSs like SSIIIa, SSII, and SSIV (Liu et al, 2021). SSI, SSIIa, SSIIIa, BEI, and BEIIb function specifically in elongating or synthesizing A chains, B1 chains, B2 chains, or longer chains (Nakamura et al, 2005;Fujita et al, 2006;Fujita et al, 2007;Jeon et al, 2010).…”

“…HT during grain filling can lead to reduced yield, increased chalkiness, and varied amylose content (AC) and starch structure (Zhang et al, 2016). AC has been found either increased or decreased when exposed to HT depending on rice variety (Cheng et al, 2005;Lin et al, 2010;Liu et al, 2021). Zhao et al (2020) found that ssIIIa-RNAi affected the susceptibility of grain chalky occurrence to HT exposure due to the relatively sensitive response of ADPglucose pyrophosphorylase (AGPase) and SSI to HT exposure and induced significant decreases in AAC and a larger decline in the proportion of DP <12 under HT relative to wild type (WT).…”

Strategies for indica rice adapted to high-temperature stress in the middle and lower reaches of the Yangtze River

“…Heat injury caused by climate warming is a major contributor to the decreases in rice yield and quality (Liu et al, 2021). If the temperature during the vegetative growth period of rice exceeds 35°C, tiller production decreases, the rate of growth in plant height declines, the growth of aboveground and underground plant parts is reduced, and the overall rice development period is shortened.…”